The climate crisis and the Covid-19 pandemic have created a perfect storm, changing people’s attitudes to offices and focussing the industry on radically rethinking how buildings consume energy and how they are ventilated.
I’ve been a building services engineer for 40 years. Throughout that time, the services in offices have been a by-product of how the buildings are designed and used: they’re often, essentially, glass boxes that face the sun and are packed with people and equipment. This has demanded they be cooled using space-efficient chilled water systems, and therefore sealed with a minimum of fresh air brought in for ventilation.
But that approach has reached the end of the road. The London Energy Transformation Initiative (LETI) targets an energy use of 55 kWh/m2 for office buildings if we’re to achieve net zero. Today, a typical office building uses four to five times this amount, so we’ll have to get a lot smarter about how buildings are supplied and serviced.
We can do things like reducing general levels of lighting in favour of task lighting and making use of the fact that modern devices such as tablet computers last a whole working day on a single charge. And we can use smart technology – for example using location-based services to understand how many people are in which areas of a building and tailor services to that demand in real time.
The most critical thing, though, is fresh air; with the UK’s temperate climate, it provides the free cooling needed to achieve the LETI target for over 80% of the year and creates healthy environments inside buildings. While openable windows have some advantages, getting fresh air consistently deep inside buildings requires mixed-mode underfloor air systems.
Clients are embracing this approach, which can be retrofitted to existing buildings, in part because of demand from occupants. A generation of office workers is concerned about the climate crisis, and many have spent a year experiencing the flexibility and freedom that working from home can bring. In our own business, just 2% of people said they would like to go back to working five days a week in the office.
It’s likely that, in the future, offices will become places to meet with colleagues and discuss ideas, rather than places to sit and work for hours on end. Releasing our buildings from being sealed up against the outside world and moving them from chilled-water cooling to all-air systems that respond to the climate will ensure they’re fit for a net-zero future of flexible office working.